Conventionally, there has been known a fuel tank disposed between a steering handlebar and a seat of a motorcycle as a saddled vehicle to be formed of a steel plate material (steel plate).
Patent Literature 1 discloses a fuel tank constituted of two parts split in a vertical direction. Usually, the fuel tank is formed such that press molding is performed on a steel plate punched out in a predetermined shape to form an upper half body and a lower half body, and end portions of both half bodies are welded together.